摘要
目的提高铝合金塑性成形性能,解决高速成形贴模缺陷。方法设计一种两步高速拉伸试样,在液压式伺服高速拉伸机上开展2次拉伸实验,并采用非接触式光学测量技术(Digital image correlation,DIC)测量全场应变,利用数值模型确定拉伸速度,获得期望的预拉伸应变率和应变。将单次高速拉伸性能与2次不同应变率和预应变下的高速拉伸性能进行对比。结果铝合金材料在2次高速拉伸下的性能明显好于单次拉伸,抗拉强度增加了10%,断裂应变增加了14.5%。结论设计的试样能满足2次高速拉伸的要求,试样预拉伸区域的尺寸和拉伸速度会影响试样的预应变、预应变率以及最终的断裂应变。
This paper aims to improve the plasticity of aluminum alloy forming and to solve the defect of die fitting in high-speed forming.In this paper,two-step tensile experiments were carried out on a hydraulic servo high speed tensile machine with a designed two-step high-speed tensile specimen,and the filed strain was measured by digital image correlation(DIC)sys-tem with a high speed camera.The numerical model was used to guide the setting of tensile velocities in the experiment so as to obtain the desired strain rates and strains after pre-stretching.The tensile properties of the specimens were compared with those of the specimens under single high-speed tension and two steps of different strain rates and pre-strains.Conclusion could be made that the properties of aluminum alloy under two-step high speed stretching were better than that of single stretching.And the tensile strength increased by 10%and the fracture strain increased by 14.5%.The results showed that the designed specimen could meet the requirements of two-step stretching.The size and tensile speed of the specimen pre-tension area would affect the specimen pre-strain and pre-strain rate,as well as the final fracture strain.
作者
郑月
邓桦坤
杨帅帅
崔俊佳
李光耀
ZHENG Yue;DENG Hua-kun;YANG Shuai-shuai;CUI Jun-jia;LI Guang-yao(State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China)
出处
《精密成形工程》
北大核心
2021年第4期23-28,共6页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(51975202)。
关键词
铝合金
高速拉伸
多步成形
断裂应变
aluminum alloy
high speed stretching
multi-step forming
fracture strain